From 7402c1c05eab046c8aa62d2ae641fc6c88013a4b Mon Sep 17 00:00:00 2001 From: Jon Roelofs Date: Wed, 1 Sep 2021 16:49:20 -0700 Subject: [PATCH] Revert "[AArch64][GlobalISel] Legalize bswap <2 x i16>" This reverts commit 5cd63e9ec2a385de2682949c0bbe928afaf35c91. https://bugs.llvm.org/show_bug.cgi?id=51707 The sequence feeding in/out of the rev32/ushr isn't quite right: _swap: ldr h0, [x0] ldr h1, [x0, #2] - mov v0.h[1], v1.h[0] + mov v0.s[1], v1.s[0] rev32 v0.8b, v0.8b ushr v0.2s, v0.2s, #16 - mov h1, v0.h[1] + mov s1, v0.s[1] str h0, [x0] str h1, [x0, #2] ret --- .../AArch64/GISel/AArch64LegalizerInfo.cpp | 45 +------------------ .../AArch64/GISel/AArch64LegalizerInfo.h | 2 - .../AArch64/GlobalISel/legalize-bswap.mir | 27 ----------- .../GlobalISel/legalizer-info-validation.mir | 4 +- 4 files changed, 3 insertions(+), 75 deletions(-) diff --git a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp index 91c3306b54b5..990359fa7bcb 100644 --- a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp +++ b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp @@ -110,8 +110,7 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST) getActionDefinitionsBuilder(G_BSWAP) .legalFor({s32, s64, v4s32, v2s32, v2s64}) .widenScalarToNextPow2(0) - .clampScalar(0, s32, s64) - .customIf(typeIs(0, v2s16)); // custom lower as G_REV32 + G_LSHR + .clampScalar(0, s32, s64); getActionDefinitionsBuilder({G_ADD, G_SUB, G_MUL, G_AND, G_OR, G_XOR}) .legalFor({s32, s64, v2s32, v4s32, v4s16, v8s16, v16s8, v8s8}) @@ -791,8 +790,6 @@ bool AArch64LegalizerInfo::legalizeCustom(LegalizerHelper &Helper, case TargetOpcode::G_LOAD: case TargetOpcode::G_STORE: return legalizeLoadStore(MI, MRI, MIRBuilder, Observer); - case TargetOpcode::G_BSWAP: - return legalizeBSwap(MI, MRI, MIRBuilder); case TargetOpcode::G_SHL: case TargetOpcode::G_ASHR: case TargetOpcode::G_LSHR: @@ -1047,46 +1044,6 @@ bool AArch64LegalizerInfo::legalizeLoadStore( return true; } -bool AArch64LegalizerInfo::legalizeBSwap(MachineInstr &MI, - MachineRegisterInfo &MRI, - MachineIRBuilder &MIRBuilder) const { - assert(MI.getOpcode() == TargetOpcode::G_BSWAP); - - // The <2 x half> case needs special lowering because there isn't an - // instruction that does that directly. Instead, we widen to <8 x i8> - // and emit a G_REV32 followed by a G_LSHR knowing that instruction selection - // will later match them as: - // - // rev32.8b v0, v0 - // ushr.2s v0, v0, #16 - // - // We could emit those here directly, but it seems better to keep things as - // generic as possible through legalization, and avoid committing layering - // violations by legalizing & selecting here at the same time. - - Register ValReg = MI.getOperand(1).getReg(); - assert(LLT::fixed_vector(2, 16) == MRI.getType(ValReg)); - const LLT v2s32 = LLT::fixed_vector(2, 32); - const LLT v8s8 = LLT::fixed_vector(8, 8); - const LLT s32 = LLT::scalar(32); - - auto Undef = MIRBuilder.buildUndef(v8s8); - auto Insert = - MIRBuilder - .buildInstr(TargetOpcode::INSERT_SUBREG, {v8s8}, {Undef, ValReg}) - .addImm(AArch64::ssub); - auto Rev32 = MIRBuilder.buildInstr(AArch64::G_REV32, {v8s8}, {Insert}); - auto Bitcast = MIRBuilder.buildBitcast(v2s32, Rev32); - auto Amt = MIRBuilder.buildConstant(v2s32, 16); - auto UShr = - MIRBuilder.buildInstr(TargetOpcode::G_LSHR, {v2s32}, {Bitcast, Amt}); - auto Zero = MIRBuilder.buildConstant(s32, 0); - auto Extract = MIRBuilder.buildExtractVectorElement(s32, UShr, Zero); - MIRBuilder.buildBitcast({MI.getOperand(0).getReg()}, Extract); - MI.eraseFromParent(); - return true; -} - bool AArch64LegalizerInfo::legalizeVaArg(MachineInstr &MI, MachineRegisterInfo &MRI, MachineIRBuilder &MIRBuilder) const { diff --git a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.h b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.h index 78fc24559d71..35456d95dc2b 100644 --- a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.h +++ b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.h @@ -35,8 +35,6 @@ class AArch64LegalizerInfo : public LegalizerInfo { MachineInstr &MI) const override; private: - bool legalizeBSwap(MachineInstr &MI, MachineRegisterInfo &MRI, - MachineIRBuilder &MIRBuilder) const; bool legalizeVaArg(MachineInstr &MI, MachineRegisterInfo &MRI, MachineIRBuilder &MIRBuilder) const; bool legalizeLoadStore(MachineInstr &MI, MachineRegisterInfo &MRI, diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-bswap.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-bswap.mir index ab8e33ddbcf7..ad61ecd19dba 100644 --- a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-bswap.mir +++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-bswap.mir @@ -25,33 +25,6 @@ body: | RET_ReallyLR implicit $w0 ... --- -name: bswap_2xi16 -tracksRegLiveness: true -body: | - bb.1: - liveins: $s0 - - ; CHECK-LABEL: name: bswap_2xi16 - ; CHECK: liveins: $s0 - ; CHECK: [[COPY:%[0-9]+]]:_(<2 x s16>) = COPY $s0 - ; CHECK: [[DEF:%[0-9]+]]:_(<8 x s8>) = G_IMPLICIT_DEF - ; CHECK: [[INSERT_SUBREG:%[0-9]+]]:_(<8 x s8>) = INSERT_SUBREG [[DEF]](<8 x s8>), [[COPY]](<2 x s16>), %subreg.ssub - ; CHECK: [[REV32_:%[0-9]+]]:_(<8 x s8>) = G_REV32 [[INSERT_SUBREG]] - ; CHECK: [[BITCAST:%[0-9]+]]:_(<2 x s32>) = G_BITCAST [[REV32_]](<8 x s8>) - ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 16 - ; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C]](s32), [[C]](s32) - ; CHECK: [[LSHR:%[0-9]+]]:_(<2 x s32>) = G_LSHR [[BITCAST]], [[BUILD_VECTOR]](<2 x s32>) - ; CHECK: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 0 - ; CHECK: [[EVEC:%[0-9]+]]:_(s32) = G_EXTRACT_VECTOR_ELT [[LSHR]](<2 x s32>), [[C1]](s64) - ; CHECK: [[BITCAST1:%[0-9]+]]:_(<2 x s16>) = G_BITCAST [[EVEC]](s32) - ; CHECK: $s0 = COPY [[BITCAST1]](<2 x s16>) - ; CHECK: RET_ReallyLR - %0:_(<2 x s16>) = COPY $s0 - %1:_(<2 x s16>) = G_BSWAP %0 - $s0 = COPY %1(<2 x s16>) - RET_ReallyLR -... ---- name: bswap_s32_legal tracksRegLiveness: true body: | diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir index 4b2629b78099..3dd305c2b15f 100644 --- a/llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir +++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir @@ -564,8 +564,8 @@ # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected # DEBUG-NEXT: G_BSWAP (opcode {{[0-9]+}}): 1 type index, 0 imm indices -# DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected -# DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected +# DEBUG-NEXT: .. the first uncovered type index: 1, OK +# DEBUG-NEXT: .. the first uncovered imm index: 0, OK # DEBUG-NEXT: G_BITREVERSE (opcode {{[0-9]+}}): 1 type index, 0 imm indices # DEBUG-NEXT: .. the first uncovered type index: 1, OK # DEBUG-NEXT: .. the first uncovered imm index: 0, OK